Wire material and production process thereof

Abstract

The embodiment of the invention discloses a wire material and a production process thereof, and the wire material comprises the following components: a base material: 47-55 parts of polyvinyl chloride resin; 40 to 45 parts of a plasticizer; 3-5 parts of a stabilizer; 1.2 to 2 parts of a flame retardant; and 0.8-1 part of other materials, wherein the other materials comprise one or more of a lubricant, an antioxidant, a filling agent and a coloring agent. The embodiment of the invention further provides a production process of the wire material, and the problem that flexibility, flame retardance and mechanical strength of an existing PVC wire cannot be considered at the same time is solved by optimizing a material formula and production process parameters.

Description

Technical Field

[0001] The invention relates to the technical field of wire material and production, in particular to a wire material and a production process thereof. Background Art

[0002] With the rapid development of the electronic equipment field, the performance requirements for connecting wires are increasing. Although traditional polyvinyl chloride (PVC) wires have the advantages of low cost and good processing performance, they have problems such as insufficient flexibility, limited flame retardancy, and poor mechanical strength. In actual use, ordinary PVC wires are easily broken due to bending and stretching. It is difficult to meet the flame retardant requirements under high temperature or fire environments, there are safety hazards, and they cannot meet the needs of high-end application scenarios.

[0003] In order to improve the performance of PVC wires, various additives are usually added in the prior art. For example, flexibility is improved by increasing the amount of plasticizer, but excessive addition of plasticizer will lead to a decrease in the mechanical properties of the wire, and plasticizer migration is likely to occur, affecting the service life of the wire; in terms of flame retardancy, some technologies use halogen-containing flame retardants. Although the flame retardant effect is significant, a large amount of toxic and harmful gases will be released during combustion, which does not meet environmental protection requirements. In addition, the prior art still has deficiencies in the coordinated optimization of material formulation and production process, and it is difficult to achieve a balance between flexibility, flame retardancy and tensile strength. Therefore, it is urgent to develop a new type of wire and its production process that has high flexibility, excellent flame retardancy and high strength. Summary of the invention

[0004] The embodiment of the present invention aims to provide a modified material for highly flexible, tensile and flame-retardant wire and a production process thereof, and solves the problem that the flexibility, flame retardancy and mechanical strength of existing PVC wire cannot be taken into account at the same time by optimizing the material formula and production process parameters.

[0005] An embodiment of the present invention provides a wire material, including:

[0006] Base material: 47-55 parts of polyvinyl chloride resin;

[0007] Plasticizer: 40-45 parts;

[0008] Stabilizer: 3-5 parts;

[0009] Flame retardant: 1.2-2 parts;

[0010] Other materials: 0.8-1 part, the other materials include one or more of lubricants, antioxidants, fillers and colorants.

[0011] Furthermore, the lubricant is at least one of calcium stearate or polyethylene wax, and the added amount is 0.3-0.5 parts.

[0012] Further, the flame retardant is a halogen-free flame retardant system, comprising a mixture of aluminum hypophosphite and melamine cyanurate, and the mass ratio of the two is (1.5 - 2):1.

[0013] Further, the proportion of aluminum hypophosphite in the flame retardant is 0.8 - 1.2 parts, and the proportion of melamine cyanurate is 0.4 - 0.8 parts.

[0014] Further, the stabilizer is a calcium-zinc composite stabilizer.

[0015] The embodiment of the present invention also provides a wire production process for the above wire material, including:

[0016] Drying the polyvinyl chloride resin and the masterbatch through a vacuum conveying device for 1 - 3 hours, and controlling the moisture content ≤ 0.3%;

[0017] Using a single-screw extruder with a length-diameter ratio of 20 - 25, melting under the conditions of a feeding zone temperature of 130 - 150 °C, an intermediate zone temperature of 160 - 165 °C, a head zone temperature of 160 - 170 °C, and a die head temperature of 130 - 140 °C, and passing through a screen mesh of 80 - 120 meshes;

[0018] Co-extruding and covering the stranded wire core with the molten material through a twin-screw extruder, the wire core is a stranded body of 2 or more plated metal copper wires, the stranding pitch ratio is 10 - 20, and water cooling or air cooling is used for cooling and shaping.

[0019] Further, the masterbatch is a high-concentration masterbatch, and the color uniformity deviation of the dispersed product is ≤ 5%.

[0020] Further, the screw speed of the twin-screw extruder is 20 - 50 r / min, and the melt pressure is controlled at 8 - 15 MPa to ensure that the material dispersion uniformity is ≥ 98%.

[0021] Further, the stranded wire core adopts concentric layer stranding, the stranding directions of adjacent layers are opposite, and after 3 - 4 compacting processes, the compacting coefficient is ≥ 0.9 and the conductor filling rate is ≥ 90%.

[0022] Further, the extrusion molding process includes:

[0023] Using a double-channel die head for co-extrusion and covering of the inner and outer layers, and controlling the die head orifice temperature at 120 - 130 °C;

[0024] The matching ratio of the traction speed to the extrusion speed is (1.0 - 1.2):1 to ensure that the thickness uniformity deviation of the wire coating layer is ≤ 3%.

[0025] The wire made of the wire material and its production process provided by the embodiment of the present invention has better high flexibility, tensile resistance, wear, scratch and bend resistance, and flame retardant properties. Description of the Drawings

[0026] To more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings, where:

[0027] Figure 1 It is a flowchart for manufacturing an exemplary wire provided by an embodiment of the invention. Specific embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0029] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0030] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0031] Embodiment 1: Wire material formula and preparation

[0032] Material formula (by weight): Base material: 50 parts of polyvinyl chloride resin; Plasticizer: 43 parts of dioctyl phthalate (DOP); Stabilizer: 4 parts of calcium-zinc composite stabilizer; Flame retardant: 1.0 part of aluminum hypophosphite + 0.6 part of melamine cyanurate (MCA) (mass ratio 1.67:1); Other materials: 0.4 part of calcium stearate (lubricant), 0.3 part of antioxidant, 0.3 part of calcium carbonate (filler).

[0033] Preparation process:

[0034] (1) Pretreatment of raw materials

[0035] The polyvinyl chloride resin and high-concentration red color masterbatch are dried for 2 hours through a vacuum conveying device, and the moisture content of the material is controlled to be ≤ 0.25%.

[0036] (2) Melting and extrusion

[0037] A single-screw extruder with a length-diameter ratio of 22:1 is used, and the temperature zones are set as follows:

[0038] Feeding zone: 140 °C

[0039] Middle zone: 162 °C

[0040] Die head zone: 165 °C

[0041] Die head: 135 °C

[0042] The molten material is filtered through a 100-mesh screen and then transported to a twin-screw extruder.

[0043] (3) Coating of the wire core

[0044] Parameters of the twin-screw extruder: screw speed 35 r / min, melt pressure 12 MPa, melt dispersion uniformity ≥ 99%. Wire core structure: 4 tinned copper conductors are concentrically stranded, and the stranding directions of adjacent layers are opposite (left-handed for the outer layer and right-handed for the inner layer), the stranding pitch ratio is 15, it is calendered by 3 sets of compacting rollers, the compacting coefficient is 0.92, and the conductor filling rate is 92%. Co-extrusion process: A double-channel die head is used for coating, the outer die temperature is 125 °C, and the ratio of the drawing speed to the extrusion speed is 1.1:1.

[0045] (4) Cooling and shaping:

[0046] The coated wire is cooled through an air-cooling device, and the outer diameter deviation of the wire is ≤ 2.5%, and the surface is smooth without bubbles.

[0047] Example 2: Preparation of high flame-retardant wire

[0048] Material formula (by weight)

[0049] Base material: 48 parts of polyvinyl chloride resin; Plasticizer: 45 parts of dioctyl terephthalate (DOTP); Stabilizer: 3 parts of calcium-zinc composite stabilizer; Flame retardant: 1.2 parts of aluminum hypophosphite + 0.8 part of melamine cyanurate (MCA) (mass ratio 1.5:1); Other materials: 0.3 part of polyethylene wax (lubricant), 0.2 part of carbon black (colorant), 0.3 part of aluminum silicate (filler).

[0050] Process adjustment

[0051] The die head temperature of the single-screw extruder is adjusted to 130 °C, and the melt pressure of the twin-screw extruder is increased to 14 MPa; the pitch ratio of the core stranding is adjusted to 20, water cooling is adopted, and the deviation of the uniformity of the coating layer thickness is ≤ 2.8%.

[0052] Example 3: Preparation of wire with high chromaticity uniformity

[0053] Material formula (by weight):

[0054] Base material: 55 parts of polyvinyl chloride resin; Plasticizer: 40 parts of diisodecyl phthalate (DIDP); Flame retardant: 0.8 part of aluminum hypophosphite + 0.4 part of melamine cyanurate (MCA) (mass ratio 2:1); Color masterbatch: blue high-concentration color masterbatch, with the deviation of color uniformity after dispersion ≤ 4.2%.

[0055] Key process points

[0056] The drying time of the raw materials is extended to 3 hours, and the moisture content is ≤ 0.15%; the rotation speed of the twin-screw extruder is reduced to 25 r / min, the melt pressure is 8 MPa, and the dispersion uniformity is ≥ 98.5%.

[0057] Example 4: Preparation of ultra-compact stranded conductor wire

[0058] Core structure parameters

[0059] Conductor: 7 silver-plated copper wires are stranded in 4 layers, and the stranding directions are alternately right-left-right-left; Stranding process: After 4 compacting processes, the compacting coefficient is 0.95, and the conductor filling rate is 95%.

[0060] Optimization of the coating process

[0061] The die head die temperature is 130 °C, the ratio of the drawing speed to the extrusion speed is 1.2:1, and the deviation of the coating layer thickness is ≤ 2.0%.

[0062] The wires prepared in Examples 1-4 are tested, and the results are as follows:

[0063] Flame retardancy (UL94 vertical burning): V-0 level, burning time < 2 s, no dripping;

[0064] Mechanical properties:

[0065] Tensile strength: 16.2 - 18.5 MPa

[0066] Elongation at break: 265% - 280%

[0067] Electrical properties: DC resistance of conductor ≤ 0.017 Ω / m (20 °C);

[0068] Aging resistance (thermal aging at 70 °C × 168 h): Retention rate of tensile strength ≥ 96%, no cracks on the surface.

[0069] While the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive, terms. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be construed broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A wire material, characterized in that, Including: Base material: 47 - 55 parts of polyvinyl chloride resin; Plasticizer: 40 - 45 parts; Stabilizer: 3 - 5 parts; Flame retardant: 1.2 - 2 parts; Other materials: 0.8 - 1 part, and the other materials include one or more of lubricants, antioxidants, fillers and colorants.

2. The wire material according to claim 1, characterized in that, The lubricant is at least one of calcium stearate or polyethylene wax, and the addition amount is 0.3 - 0.5 part.

3. The wire material according to claim 1, characterized in that, The flame retardant is a halogen-free flame retardant system, which contains a mixture of aluminum hypophosphite and melamine cyanurate, and the mass ratio of the two is (1.5 - 2):

1.

4. The wire material according to claim 1, characterized in that, In the flame retardant, the proportion of aluminum hypophosphite is 0.8 - 1.2 parts, and the proportion of melamine cyanurate is 0.4 - 0.8 part.

5. The wire material according to claim 1, characterized in that, The stabilizer is a calcium-zinc composite stabilizer.

6. A wire production process for preparing the wire material according to any one of claims 1-5, characterized in that, Including: Dry the polyvinyl chloride resin and the masterbatch through a vacuum conveying device for 1 - 3 hours, and control the moisture content ≤ 0.3%; Use a single-screw extruder with a length-diameter ratio of 20 - 25, and melt at a temperature of 130 - 150 °C in the feeding zone, 160 - 165 °C in the middle zone, 160 - 170 °C in the head zone, and 130 - 140 °C in the die head zone, and the mesh size of the sieve is 80 - 120 meshes; Co-extrude and wrap the stranded wire core with the molten material through a twin-screw extruder. The wire core is a stranded body of 2 or more metal-coated copper wires, the stranding pitch ratio is 10 - 20, and water cooling or air cooling is used for cooling and shaping.

7. The wire production process according to claim 6, characterized in that, The masterbatch is a high-concentration masterbatch, and the color uniformity deviation of the dispersed product is ≤ 5%.

8. The wire production process according to claim 6, characterized in that, The screw speed of the twin-screw extruder is 20 - 50 r / min, and the melt pressure is controlled at 8 - 15 MPa to ensure that the material dispersion uniformity is ≥ 98%.

9. The wire production process according to claim 6, characterized in that, The stranded wire core adopts concentric layer stranding, the stranding directions of adjacent layers are opposite, and after 3 - 4 compacting processes, the compacting coefficient is ≥ 0.9, and the conductor filling rate is ≥ 90%.

10. The wire production process according to claim 6, characterized in that, The extrusion molding process includes: Use a double-channel die head for co-extrusion and wrapping of the inner and outer layers, and control the die head orifice temperature at 120 - 130 °C; The matching ratio of the traction speed to the extrusion speed is (1.0 - 1.2):1 to ensure that the thickness uniformity deviation of the wire coating layer is ≤ 3%.

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